Australia's government plans to hold a referendum within three years on whether to amend its constitution to acknowledge the Aborigines as the first Australians, the prime minister said today.

Julia Gillard said the time was right to amend the constitution to acknowledge that "the first people of our nation have a unique and special place" because such a referendum had broad support in parliament. The Australian parliament needs to endorse proposals to hold referendums.

One of the first acts undertaken by the Labor government after its 2007 parliament election victory was to formally apologise to Aborigines for injustices during the more than 200 years since British colonists arrived.

An expert panel including Aborigines will soon be appointed and report to the government next year on the wording of the referendum. The vote will take place before or during the next general election in late 2013, the prime minister said.

"Support this widespread across the parliament means we have a once-in-50-years opportunity for our country," Gillard told reporters.

Australians are reluctant to change their constitution and only eight of the 44 referendums that have been voted on since 1901 have succeeded.

A referendum was defeated in 1999 that would that would have added a preamble to the constitution honouring Aborigines as "the nation's first people for their deep kinship with their lands and for their ancient and continuing cultures which enrich the life of our country".

Larissa Behrendt, an Aboriginal professor at Sydney's University of Technology, predicted that Aborigines will argue for indigenous rights to be entrenched in the text of the constitution rather than a symbolic acknowledgment in a preamble.

"The danger is that if you put the question up about constitutional protection of indigenous people and it fails, it sends a very bad message to the Aboriginal community and what is supposed to be an act of recognition of the special place of Aboriginal people in Australian society becomes a further insult," she said.